In an embodiment, a single-sided or double-sided moving magnet haptic engine comprises: a frame; one or more magnetic field sources mounted to the frame and operable to generate a magnetic field and a back electromotive force (EMF) voltage; a magnetic mass positioned within the frame and operable to move within the frame along a movement axis; a comparator mounted to the frame, the comparator operable to detect the magnetic field and to generate a signal indicating a crossing of one or more magnetic references by the magnetic field; and a processor coupled to the one or more sensors and operable to estimate a displacement of the magnetic mass on the movement axis based on the back EMF voltage and the signal. Other embodiments are directed to a single-sided or double-sided moving coil haptic engine.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A haptic engine comprising: a frame; one or more magnetic field sources mounted to the frame and operable to generate a magnetic field and a back electromotive force (EMF) voltage; a magnetic mass positioned within the frame and operable to move within the frame along a movement axis; a comparator mounted to the frame, the comparator operable to detect the magnetic field and to generate a signal indicating a crossing of one or more magnetic references by the magnetic field; and a processor operable to implement a state estimator or filter for estimating a displacement of the magnetic mass on the movement axis based on measurements of the back EMF voltage and the signal from the comparator, wherein the state estimator or filter uses the signal from the comparator to correct the estimated mass displacement.
2. The haptic engine of claim 1 , wherein the one or more magnetic field sources include one or more coils, the coils generating the magnetic field in response to current flowing through the one or more coils, and wherein the back EMF voltage is induced by the current flowing through the one or more coils.
3. The haptic engine of claim 2 , wherein the frame includes two opposing frame portions that are parallel to the movement axis, and the magnetic mass is constrained to move between the frame portions in a direction parallel to the frame portions.
4. The haptic engine of claim 3 , wherein one or more coils are mounted to one of the opposing frame portions.
5. The haptic engine of claim 3 , wherein one or more coils are mounted to each of the opposing frame portions.
6. The haptic engine of claim 1 , wherein the comparator is operable to toggle an output signal each time the magnetic reference is crossed.
7. The haptic engine of claim 6 , wherein comparator includes a Hall sensing element.
8. The haptic engine of claim 7 , wherein the comparator is duty cycled to save power.
9. The haptic engine of claim 7 , wherein the comparator is a unipolar comparator.
10. The haptic engine of claim 7 , wherein the comparator is an omnipolar comparator and the reference displacement is determined by a ratio of EMF sensed displacements at switching edges.
11. The haptic engine of claim 1 , wherein the processor is configurable to compensate for hysteresis of the comparator.
12. A haptic engine comprising: a frame; a first set of magnets mounted to the frame; a mass positioned within the frame and operable to move within the frame along a movement axis, the mass including a second set of magnets and one or more magnetic field sources operable to generate a magnetic field and a back electromotive force (EMF) voltage; a comparator mounted to the frame, the comparator operable to detect the magnetic field and to generate a signal indicating a crossing of one or more magnetic references by the magnetic field; and a processor coupled to one or more sensors and operable to implement a state estimator or filter for estimating a displacement of the magnetic mass on the movement axis based on measurements of the back EMF voltage and the signal from the comparator, wherein the state estimator or filter uses the signal from the comparator to correct the estimated mass displacement.
13. The haptic engine of claim 12 , wherein the one or more magnetic field sources include one or more coils, the coils generating the magnetic field in response to current flowing through the one or more coils, and wherein the back EMF voltage is induced by the current flowing through the one or more coils.
14. The haptic engine of claim 13 , wherein the frame includes two opposing frame portions that are parallel to the movement axis, and the magnetic mass is constrained to move between the frame portions in a direction parallel to the frame portions.
15. The haptic engine of claim 14 , wherein one or more magnets in the first set of magnets are mounted to one of the opposing frame portions.
16. The haptic engine of claim 14 , wherein one or more magnets in the first set of magnetics are mounted to each of the opposing frame portions.
17. The haptic engine of claim 12 , wherein the comparator is operable to toggle an output signal each time the magnetic reference is crossed.
18. The haptic engine of claim 17 , wherein comparator includes a Hall sensing element.
19. The haptic engine of claim 18 , wherein the comparator is duty cycled to save power.
20. The haptic engine of claim 18 , wherein the comparator is a unipolar comparator.
21. The haptic engine of claim 18 , wherein the comparator is an omnipolar comparator and the reference displacement is determined by a ratio of EMF sensed displacements at switching edges.
22. The haptic engine of claim 12 , wherein the processor is configurable to compensate for hysteresis of the comparator.
23. A method comprising: generating, by one or more magnetic field sources mounted to a frame of a haptic engine, a magnetic field and a back electromotive force (EMF) voltage; driving a mass to move within the frame along a movement axis, the movement of the mass inducing a back electromotive force (EMF) voltage; detecting, using a comparator, at least a directional component of the magnetic field and generating a signal indicating a crossing of one or more magnetic references by the directional component of the magnetic field; and estimating, using a state estimator or filter, a displacement of the magnetic mass on the movement axis based on measurements of the back EMF voltage and the signal from the comparator, wherein the state estimator or filter uses the signal from the comparator to correct the estimated mass displacement.
24. The method of claim 23 , wherein the magnetic field sources are coils mounted to the frame and the mass includes magnetic portions.
25. The method of claim 23 , wherein the magnetic field sources include at least one coil mounted to the mass and magnets are mounted to the frame and the mass.
26. The method of claim 23 , wherein a unipolar or omnipolar comparator detects the at least one directional component of the magnetic field and generates a signal indicating a crossing of one or more magnetic references by the directional component of the magnetic field.
27. The method of claim 26 , wherein the comparator is duty cycled to save power.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 7, 2017
August 18, 2020
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.